1. Field of the Invention
The present invention relates to a tailstock device provided with a dressing device for a grinding machine.
2. Description of the Prior Art
Conventionally, the dressing tool is mounted on the side of the tailstock device secured on the table of the grinding machine. In order to dress the grinding wheel, the table mounting the tailstock device thereon is longitudinally traversed. Since the dressing tool is moved by utilizing traversing movement of the table, this arrangement is effective particularly in a super-precision grinding operation required for high cylindricity.
On the other hand, there is a limitation in mounting and adjusting the dressing tool. More specifically, it is impossible to adjust the tip of the dressing tool into a position corresponding to the finished surface of the workpiece because of the existence of the ram provided on the tailstock device for advancing and retracting the center. Accordingly, in case of dead stop grinding wherein the wheel movement toward the workpiece is stopped at the dead stop position to finish the workpiece, the grinding wheel at such dead stop position is spaced apart from the dressing position. As a result, after the dressing operation, the difference between the dead stop position and the dressing position of the grinding wheel must be compensated for in order to initiate the dead stop grinding. This compensation may cause a positioning error of the grinding wheel, which results in lowering the accuracy of the workpiece.